The invention relates to a roll for spreading and braking or slowing down pourable materials.
In the production of material panels of spreadable or pourable materials, such as in the production of chipboard panels for example, a mixture of wood chips or fibrous materials and binder agents are spread into a fleece layer on a substrate or support. For this, the substrate is usually a continuously moved conveyor belt, which transports the chip fleece to a press. A problem in the production of such material panels exists in achieving a uniform spreading and mixing of the chips provided with binder agents, in order to spread a flat or planar uniform layer onto the transport belt. To achieve this, a so-called spoke roll is known as a spreading roll which is arranged in a spreading chamber, from the EP 0 800 901 A1. This spoke roll is characterized in that it consists of at least two end disks, between which spokes are arranged under stress over the entire spreading width. The wood particles provided with binder agents are very uniformly intermixed by the rotating spreading roll, so that a uniform chip fleece is spreadable therewith.
In recent times, frequently recycled materials are being processed into chips, which often contain longer fiber components and foreign materials such as hairs and synthetic fibers. Thus, these fibers and foreign materials become more and more wrapped or wound around the thin rods or spokes and thus progressively ever more plug or clog the spreading roll. For this reason it is necessary to clean the wound-up fibers off of the spokes of the spreading roll, at certain time intervals. This is very complicated or time-consuming and cost intensive because the panel production must be interrupted during this time.
Therefore, the invention is based on the object, to improve a spreading roll of the above described type in such a manner so that to the extent possible no contaminants become caught or deposited on the spokes or rods. This object has been achieved according to the invention in a spreading roll comprising two end disks, plural elongate members extending between the two end disks, and a respective loose sheath loosely arranged on and extending along each one of the plural elongate members, which may have the form of spokes, rods, pipes or cords.
The invention has the advantage, due to the inventive loose jacketing or sheathing of the spokes, that the spreading roll basically does not need to be constructively altered in order to prevent such contaminations of the spokes. Therefore, in an advantageous manner, also existing spoke rolls can be retrofitted with such a winding or wrapping protection.
Since the chips turbulently mix with one another differently in connection with wound-up spokes or rods in comparison to clean rod or spokes, therefore the quality of the spreading also varies with increasing contamination. Thus, in an advantageous manner, the jacketing or sheathing of the spokes ensures a constant spreading quality and therewith a uniform quality of the chipboard panels.
Moreover, the invention increases the operating reliability and operating life of the roll in an advantageous manner, because the weight of the spokes and of the roll will be increased by a plugged or clogged spreading roll, whereby this easily leads to spoke breaks and bearing damages.